Ground rod clamp



June 28, 1932 R l NK 1,864,688

GROUND ROD CLAMP Filed Iflarch 29 1925 WITN SSES 6 V I w M964 AMY'MQ Patented June- 28, 1932 um'reo STATES.

PATENT OFFICE 7 ROBERT J. FRANK, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T COPPER-WELD STEEL COMPANY, OF RANKIN, PENNSYLVANIA, A CORPORATION OF PENNSYL- VANIA.

GROUND ROD CLAMP Application filed March 29, 1926. Serial No. 98,056.

My invention relates to clamps for connecting ground wires to ground rods in a simple and efiicient manner.

It is among the objects of my invention to provide a clamp of the above designated character which shall comprise a simple two-piece member of rugged mechanical construction which shall be readily applicable for connecting ground wireswith ground rods, or the like, to effect a strong mechanical and efficient electrical connection of the joined members.

Another object of my invention is to provide a ground clamp of such form that the joined members will be conformed to the shape of the clamp to distort their respective contours in the region of the clamping memher and also to distort their respective contacting faces to make them complementary,

thereby assurin a maximum contacting area to provide an e cient electrical connection.

Various forms of splicing and clamping members have been heretofore proposed which mainly embody means for engaging and securely gripping a pair of electrical conductors to provide eflicient contact, and to obtain the desired result the rior art devices have been formed to the con guration of the condizictor elements for which they were desi e n accordance with my present invention I provide a ground rod clamp in the form of a sleeve having an opening of a size sufficient to convenientl receive the ground rod and having a groove or off-set portion terminating with said opening to receive or engage a. ground wire which is to be joined or connected with the ground rod, and which wire may be of various sizes or forms. I further provide a clamping member which is adapted to engage the ground rod and exert a lateral pressure thereon to bring it into intimate engagement with the ground wire and in addition to distort the ground wire in the region of its engagement with the clamp and to distort the contacting faces of the ground rod and wire by displacing the metal to conform them to the irre larities of their respective surfaces, as will i: more fully hereinafter explained.

In the accompanying drawing constituting a part hereof and in which like vreference characters designate like parts, Fig. 1 is a front elevational view of a ground clamp embodying the principles of my invention; Fig. 2 is a side elevational view thereof showing the manner of its application to a ground rod and ground wire; Fig. 3 is a cross-sectional View of the clamp and the ground rod and wire taken along the line IIIIII, Fig. 2; Figs. & and 5 are elevational views of conductor wires illustrating to enlarged scale the distortion of the metal effected by the clamp ing action.

Referring to the several figures of the drawing, the structure therein illustrated comprises a clamp in the form of a continuous sleeve 1 provided with an opening 2 extending longitudinally thereof, and having a slotted portion or groove 3 terminating therein, or in other words facing inwardly of the clamp opening. The sleeve 1 is further provided with a screw-threaded opening 4 adapted to receive a clamping screw or bolt 5 for exerting pressure on a ground rod 6 and ground wire 7 or 7 disposedand extended through the opening 2 and slot 3 of the clamp.

Ground rods to which ground wires are commonly connected are relatively thick in cross-section, and usually formed of copper,

copper-coated steel, ferrous rods, pipes and thelike. The wire for effecting a ground connection as for lightning arresters, radio circuits and other protecting systems, is of relatively small cross-section as compared with the ground rod and may comprise a single or multiple strand wire as the wires k 7 and 7. By clamping the ground rod 6 and the ground wire'7 or 7 in the manner shown in Fig. 2, the soft copper metal is readily distorted in the manner shown in Figs. 4 and 5, the portions 8 and 9 of the wire 7 indicating the shape they assume by virtue of the wire 7 being displaced in the region of the groove 3 with which it contacts, the contacting face being indicated by the depressed portion 10, Fig. 4. In addition to this conforming of themembers of the clamp, the members 6 and 7 or 7 are similarly distorted in conformity with the shape of their contacting surfaces as shown, by tg ie projection 11 Fig. 4, and the portion 12 i 5.

It ill be noted from Figure 3 that the opening 2 is only slightly greater in width than the diameter of the ground rod 6. It is very important, I have found,to have the ground rod diameter more than 80% of the width of the opening, as otherwise the rod jams to one side of the opening and a substantially true diametrical pressure is not applied through the ground rod to the ground wire. When this occurs, there is great danger of improper clamping and poor groundhe displacement of the clamped rod and wire provides a relatively large contacting surface of the cooperating members, thereby assuring efiicient electrical contact, and furthermore the distortion of the metal produces a joint of greater mechanical strength than is obtained in the function of prior art devices.

I claim:

1. The combination with a conductor, and a ground rod of materially larger diameter than the conductor, of a clamp consisting of a continuous sleeve provided with an opening of elongate uniform cross section having a minor axis slightly larger than the diameter of said rod which is arranged in one end of said opening, the interior wall of said sleeve being provided with a groove at the other end of said opening receiving said conductor in parallel with said rod, a side of said conductor projecting into said opening in contact with said rod, and a screw clamp extending through said sleeve and bearin upon said rod at said first-named end of sai clamp opening and distorting said conductor in conformity with the contour of said groove.

2. An electrical ground connection comprising two conductors, namely, a ground rod and a ground wire, and a clamp in the form of a continuous unitary sleeve extending around the ground rod and the ground wire, the sleeve having an elongated opening therein and having a channel-like conformation at one side of the recess on the long diameter thereof, there being a threaded opening in the sleeve at the opposite side thereof, and a set screw in the opening, the ground rod and the ground wire being disposed side by side in said elongated opening, one of the conductors being engaged by the set screw and the other being engaged by the channel-like side of the opening, the conductor and the sleeve being held in clamping engagement by the set screw and the ground rod being of a diameter more than 80% of the width of the slot, at least one of the conductors being permanently deformed by the pressure of the set screw.

3. An electrical ground connection comprising a ground rod, a ground wire, and a clamp in the form of a continuous unitary sleeve extending around the ground rod and the ground wire, the sleeve having an elongated opening therein through which the ground rod and the ground wire extend, there eing a threaded opening in the sleeve at one end on a long diameter of the opening and a set screw in said threaded opening, the ground rod and the ground wire being disposed side by side in said elongated opening with the ground rod adjacent the set screw, the ground wire being engaged by the side of the elongated opening opposite that where the set screw is located, said side of said elongated opening being so formed as to centralize the ground wire on said long diameter, and the ground rodbeing of a diameter more than 80% of the width of the slot, the ground wire being permanently deformed by the pressure of the set screw, whereby the ground wire conforms to the shape of the sleeve.

In testimony whereof, I sign m name.

ROBERT J. RANK. 

